Copper in a283 gr.c 1

[Ali F.]

I have a technical question about the amount of copper in A283 sheets.
In standard A283, the amount of copper is specified as at least %0.2. Of course, it is said that when copper is specified. Can anyone advise if the buyer does not specify the amount of copper to the manufacturer, the manufacturer can create the amount of copper less than %0.2 in the sheets?
What is the minimum amount of copper if not specified?

 

[MJCronin]

From an Acelor Mittal publication:

"Copper is added to steel primarily to improve the steel’s resistance to atmospheric corrosion, such as ArcelorMittal USA’s weathering steels. In the usual amount between 0.20 percent to 0.50 percent, the copper does not significantly affect the mechanical properties. In levels to 1.00 percent, copper (in combination with nickel) can increase strength by precipitation aging as in ArcelorMittal USA’s Spartan™ and A710 steels. Copper contributes to hot-shortness (unless nickel is also added) and a more adherent mill scale which adversely affects surface quality."

My understanding of this statement is that there are advantages AND disadvantages to having copper in your ASTM A283 plate ... You, the purchaser must know and understand your choices..

My understanding of ASTM Specification A283 Grade C is that plate can meet the specification with our without the copper, up to the maximum specified. It is an optional alloying metal that may or may not be required by the purchaser

Does this answer your question ?


MJCronin
Sr. Process Engineer

 

[weldstan]

In melting of scrap for steel making, copper is an inevitable constituent. Generally speaking when Cu is less than 0.20% it was not added by the Manufcturer.

 

[Ali F.]

Thank you MJCronin & weldstan.
Thanks for your explanation.
1. So if I understand correctly. Manufacturers can typically deliver less than 0.2% of copper in a283 unless the buyer or customer specifies a specific quantity.
2. My question was about the amount of copper specified in standard a283. The standard states that the minimum amount of copper is 0.2 percent for when the amount of copper is specified. Well, if we do not determine the amount of copper as a customer, does not the amount of copper less than 0.2% in the chemical analysis of a283 conflict with the standard amount?

 

[weldstan]

If copper is specified by the purchaser, the minimum is 0.2%. In this case it is obvious that the purchaser wants copper added to provide additional atmospheric corosion resistance. If the purchaser does not specify copper as an alloying element, the amount of copper need not be provided in the chemical analysis, though the material may actually have greater than 0.2% or may not depending on the amount of copper in the scrap for melting.